Compound, Composition, and Method for Protecting Skin from High Energy Visible Light

Abstract

A compound, composition, and method for the protection of skin from the harmful effects of radiation, and particularly the harmful effects of high energy visible (HEV) radiation, are disclosed. The compound is a melanin derivative that can be formulated into compositions containing the melanin derivative and a suitable carrier. The composition is topically applied to the skin to reduce the risk of photoaging and improve skin repair due to damage from radiation.

What is claimed: 
     
         1 . A melanin derivative having a high HEV absorption and a low absorption of red light, a ratio of optical density at 440 nm to optical density at 600 nm of 10 or greater, and a molecular weight of 500 to about 10,000 Daltons. 
     
     
         2 . The melanin derivative of  claim 1  wherein the melanin derivative is produced by oxidative bleaching of melanin. 
     
     
         3 . The melanin derivative of  claim 1  wherein the melanin derivative is produced by fractionation of melanin. 
     
     
         4 . The melanin derivative of  claim 1  wherein the melanin derivative is produced by oxidative bleaching and fractionation of melanin. 
     
     
         5 . The melanin derivative of  claim 1  prepared from a melanin treated with enzymes and/or from a melanin and a co-polymerizing agent that reduces electronic delocalization of melanin oligomers. 
     
     
         6 . The melanin derivative of  claim 5  wherein the melanin is a synthetic melanin. 
     
     
         7 . The melanin derivative of  claim 5  wherein the co-polymerizing agent comprises a sulfur-containing amino acid. 
     
     
         8 . The melanin derivative of  claim 5  wherein the enzyme is selected from the group consisting of tyrosinase, TRP1 (5,6-dihydroxyindole-5-carboxylic acid oxidase), TRP2 (dopachrome tautomerase), and mixtures thereof. 
     
     
         9 . A composition comprising
 (a) a melanin derivative of  claim 1 ; and   (b) a cosmetically acceptable carrier for applying the composition topically to skin.   
     
     
         10 . The composition of  claim 9  comprising about 0.001% to about 15% of the melanin derivative, by weight of the composition. 
     
     
         11 . The composition of  claim 9  further comprising at least one of a UVB blocker and a UVA blocker. 
     
     
         12 . The composition of  claim 9  further comprising a first UV blocker for blocking UVA radiation and a second UV blocker for blocking UVB radiation. 
     
     
         13 . The composition of  claim 12  wherein the UVA and UVB blockers independently are each present in an amount of about 0.25% to about 3%, by weight of the composition. 
     
     
         14 . The composition of  claim 9  wherein the first and second UV blockers comprise at least one of a benzotriazole, a benzophenone, benzoic acid, PABA, a cinnamate, a salicylate, and an avobenzone. 
     
     
         15 . A composition for topical application to mammalian skin comprising
 (a) a melanin derivative of  claim 1 ;   (b) a topically active compound; and   (c) a cosmetically acceptable carrier.   
     
     
         16 . The composition of  claim 15  wherein the melanin derivative is present in an amount of about 0.001% to about 15%, by weight of the composition. 
     
     
         17 . The composition of  claim 15  wherein the topically active compound is selected from the group consisting of a fragrance, a drug, a therapeutic agent, a skin conditioner, an antioxidant, an insect repellant, a counterirritant, a vitamin, a plant extract, an oil, an antibacterial compound, an antifungal compound, an anti-inflammatory compound, a topical anesthetic, an epidermal lipid replacement, a sunscreen, a dermatitis or skin disease medication, and mixtures thereof. 
     
     
         18 . The composition of  claim 15  wherein the topically active compound is selected from the group consisting of benzocaine, dyclonine hydrochloride, aloe vera, butamben picrate, lidocaine hydrochloride, xylocaine, providone-iodine, polymyxin b sulfate-bacitracin, zinc-neomycin sulfate-hydrocortisone, chloramphenicol, ethylbenzethonium chloride, erythromycin, lindane, benzoyl peroxide, erythromycin benzoyl peroxide, clindamycin phosphate, 5,7-dichloro-8-hydroxyquinoline, alclometasone dipropionate, betamethasone valerate, o-amino-p-toluenesulfonamide monoacetate, amcinonide, diflorasone diacetate, hydrocortisone, methylbenzethonium chloride, PEG-4 dilaurate, lanolin oil, petrolatum, mineral wax, butocouazole nitrate, haloprogin, clotrimazole, O-[(2-hydroxy-methyl)methyl]guanine, alclometasone dipropionate, betamethasone valerate, isopropyl myristate MSD, anthralin, methoxsalen, coal tar, 2-(acetyloxy)-9-fluoro-1′,2′,3′,4′-tetrahydro-1-hydroxypregna-1,4-dieno-[16,17-b]naphthalene-3,20-dione, 21-chloro-9-fluoro-1′,2′,3′,4′-tetrahydro-11b-hydroxypregna-1,4-dieno-[16z,17-b]naphthalene-3,20-dione, allantoin, salicylic acid, and mixtures thereof. 
     
     
         19 . The composition of  claim 15  wherein the topically active compound is a carotenoid. 
     
     
         20 . The composition of  claim 15  wherein the cosmetically acceptable carrier comprises a liquid. 
     
     
         21 . The composition of  claim 20  wherein the liquid comprises water, an alcohol, a glycol, a triol, a polyol, a natural or synthetic oil, and mixtures thereof. 
     
     
         22 . The composition of  claim 20  wherein the cosmetically acceptable carrier comprises a powdered bulking agent. 
     
     
         23 . A method of protecting mammalian skin from effects of high energy visible radiation comprising contacting the skin with a composition comprising:
 (a) about 0.01% to about 15%, by weight, of a melanin derivative of  claim 1 ; and   (b) a cosmetically acceptable carrier.   
     
     
         24 . The method of  claim 23  wherein the carrier comprises a liquid or a powder. 
     
     
         25 . The method of  claim 23  wherein the melanin derivative remains essentially on a surface of the skin. 
     
     
         26 . The method of  claim 23  wherein the composition is in a form of a solution, a dispersion, an emulsion, a stick, a mousse, or a gel. 
     
     
         27 . The method of  claim 23  wherein the composition protects the skin by reducing a risk of skin photo-aging and premature skin aging. 
     
     
         28 . A method of protecting a light-sensitive compound in a composition comprising adding a sufficient amount of a melanin derivative of  claim 1  to stabilize the compound against light degradation. 
     
     
         29 . The method of  claim 28  wherein the light-sensitive compound comprises avobenzone, oxybenzone, vitamin A, vitamin D, hydroquinone, kojic acid, ascorbic acid, ascorbic acid derivatives, natural plant extracts, licorice extract, blueberry extract, and mixtures thereof. 
     
     
         30 . A composition comprising
 (a) about 0.001% to about 1%, by weight, of a melanin derivative of  claim 1 ;   (b) a cosmetically acceptable carrier; and   (c) a light-sensitive compound.